Method of and device for mixing concrete.



T. L. SMITH METHOD OF AND DEVICE FOR MIXING CONCRETE.

' APPLIOATION FILED JULY 17, 1909. 1 107 237. Patented Aug.11,1914. 2 SHEETSSHEET 1.

WITNESSES:

nltmmms PETERS co. PI-ibfaurna. WASHINGTON. u. c

T. L. SMITH.

METHOD OF AND DEVICE FOR MIXING CONCRETE. APPLIOATION FILED JULY 17, 1909.

1,107,237. Patented Aug. 11,1914

2 SHEETS-SHEET 2.

WITNESSES IN VENTOR JZMM V @ZZLQX A TTORNE Y THE NORRIS PETERS PI'IOTO'LIITHO.I WASHINGTON, D C- THOMAS L. SMITH, OF MILWAUKEE, WISCONSINZ,

METHOD OF AND DEVICE FOR MIXING- CONCRETE.

Specification of Letters Patent.

Patented Aug. 11, 1914.

Application filed m 17, 1969. Serial No. 508,211.

To all whom it may concern Be it known that I, THOMAS L. SMITH, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of WVisconsin, have invented a new and useful Improvement in the Method of and Devices for Mixing Concrete, of which the following is a specification.

My invention relates to the method of mixing concrete and to the class of mixing devices in which the force of gravity only is employed, and the objects of my invention are to produce a method of mixing and a mixing device for carrying out that method,

and shall be readily portable, efficient in operation, and durable.

Several embodiments of my invention, as to the apparatus are shown in the devices illustrated in the accompanying drawings, which form a part of this specification, but I do not consider thatmy invention is limited to the particular forms and combinations of parts shown as these are merely illustrative of an apparatus for carrying out my method.

In the drawing Figure 1 shows a side elevation of one form of a complete device for mixing concrete. Fig. 2 is a view of the same device as viewed from the right hand side of Fig. 1 Fig. 3 is a plan view of the charging hopper shown in side elevation in Fig. 1. Fig. 4- is a side view of a modified form of the mixing device. Fig. 5 is a front view of the device shown in Fig. 4. Fig. 6 is a View of a part of Fig. 4. looking perpendicularly to Fig. 4.-. Fig. 7 is a side view of still another modification of the mixing device, and Fig. 8 is a front view of Fig. 7

The same letters designate the same and similar parts throughout the different views of the drawings.

A designates the charging hopper which is pivotally supported on the floor F by means of a shaft a and two boxes a. The

main body of the hopper, that is the part to the left of the shaft a is entirely open on to so that wheel barrow loads of sand, grave or crushed stone may be readily dumped in. This uncovered part. is designated by o The part of the hopper to the right of the shaft (1!. is tapered from the shaft toward its open end a This portion of the hopper is covered, said cover being designated a; a are handles by means of which the hopper may be tilted to discharge. The hopper is to be placed with its discharge end a overhangmg an aperture f in the floor F.

The mixing device B comprises a frame or ladder formed by the uprights b 6 con nected together by the cross pieces b 7/.

Supported by this ladder is a series of mixmg spouts I). b. 22., the alternate ones inclined in opposite directions, and each spout discharging into the one below. Each spout b is relatively wide at its upper end and is gradually narrowed toward its discharge end. The discharge openings are made gradually! narrower from the top of the ladder to the bottom. The entire ladder is sus pended from the floor F by means of two hooks f" which engagea boltl-g extending through the ladder and projecting from the sides thereof.

H is a receiving hopper having a gate 9 at the bottom, which gate is pivoted at p and is operated by the handle g. Two hooks 71 attached to the ladder engage a bolt it extending through the hopper, thus supporting the hopper.

In operation, the proper quantity of sand for a batch is dumped in the charging hopper A and is roughly spread over the bottom of the portion a The cement is next dumped outof its bag and roughly spread over the sand. The crushed stone or gravel is next dumped in and is also spread throughout a The proper quantity of water for the batch is next introduced and the hopper should be so placed on the floor that the-water will not run out of the discharge opening a The hopper A is then tilted on the shaft a by means of the handles a into the position shown in dotted lines in Fig. 1. While so tilted the ingredients slide down the hopper A, the shape of which changes the stream of material from a wide shallow mass to a deep narrow stream in which from it issues from the discharge opening a This change of form from a wide shallow stream to a narrow deep stream involves a most efiicient mixing action. As the material passes through the narrow orifice the relative positions of the constituent parti cles are changed, and as the narrow deep stream issues from the opening'and falls onto a relatively wide surface the stream spreads out and the relative positions of the particles are again changed. Thus every time a stream of material passes through one of these constricted orifices it underfour spoutsto give a sulficiently good mix-l mg for most purposes. I have valso shown gthe openings of the spouts as gradually regoes two deformations with their consequent mixing. Gravity furnishes the motive power for the stream and every change in the width and depth of the stream causes change of relative position of the constituent particles and consequent mixing. It is clear that a method is here involved which might even, theoretically, be carried out by hand regardless of any apparatus, and I consider my invention to embrace the method of mixing above set forth as'well as the particular form of apparatus which I have shown and described for carrying outthat method. As the material passes through the successive constrictions of the spouts b. b. it is repeatedly mixed and isfinally collected in the receiving hopper H, out of which it may be fed as desired by means of the eccentrically pivoted gate 9 operated by the handle g to swing on the pivot pins 29-. p.

I have shown a series of six spouts which I have found byexperiment to give a thoroughly etficient mixing, and I have found duced in sizefrom the top, toward the bottom.

The entire device is readil se re 'able intothree distinct parts, to wit, the charging hopper A, the mixing ladder B, and the re ceiving hopper H, and istherefore easily made portable, and readily assembled in a new location. V

In Figs. at, 5 and 6 I have shown a modified form of, the mixing part B only. In this modification the ladder frame work 6 b errig. 1 is dispensed with, and a sheet metal trough having a' bottom 6* and sides b? b is used. The constrictions are formed by strips of metal being bent into form of saw teeth as shown in Figs. 5 and 6 and lettered b These saw tooth plates are of course to be secured to the side plates 6 by rivets at the throats of the teeth, and the points of the teeth are to'be placed opposite,

each other or at least in such relation to each other, as to form a constriction. This mix- .ing trough is provided with cross pieces 6 b by means of which the trough may be hung from the floor above or may be supported from thefioor below in any approved manner.

In Figs. 7 and 8, another modification is shoWn, in which separate spouts Z). Z). are.

used but are all pointed in the same direction. The spouts are supported on a ladder frame, consisting of' the stile b b and cross This ladder frame like the mixing trough of Fig. 4 may be supported pieces 79 5.

in any way by means of the bars 6 5 In the form shown in Fig. 4 a hopper 5 is shown and in Fig. .7 a hopper I); These hoppers may be used to receive the batch from the charging hopper A of Fig. 1, or

these hoppers may be dispensed with, in which case the charging hopper A will be arranged to deliver to the mixing trough B, or the series of mixing spouts, direct.

The devices which I have here shown and described should be considered as illustrating and not limiting the invention, as many changes and variations may be made in the apparatus.

Nhat I consider as my invention and desire to secure by Letters Patent, is,

1. The method of mixing concrete which consists in assembling a batch of the ingredients in the proper proportion with the ingredients spread in successive superim-- posed. layers of equal length and width, pouring the material in a continuous str 11,111 endwise of these layers and repeatedly and alternately crowding the materials together and allowing them to spread laterally of the stream while they alternately expand and crowd together vertically, respectively, under the force of gravity.

2. A gravity concrete mixer comprising a series of spouts each inclined to the vertical" and each having a relatively wide and shallow receiving portion which tapers to a relatively narrow and deep discharge opening, the pouts being arranged one above another with the receiving portion of each in position to receive the discharge from the spout next above it.

3. A gravity concrete mixer comprising a series of spouts each inclined to the vertical and each having a relatively wide and shal low receiving portion which tapers to a relatively narrow and deep discharge opening,

the spouts being arranged one above another with the receiving portion of each in position to receive the discharge from the spout next above it, succeeding spouts being oppositely inclined to each other.

4. A gravity concrete mixer comprising a series of spouts each inclined to the vertical andeach having a relatively wide and shal-' low receiving portion which tapers to a relatively narrow and deep discharge opening, the spouts being arranged one above another with the receiving portion of each in position to receive the discharge from the spout next above it, and a charging h'opper adapted and arranged to be tilted to feed material to the receiving portion of the uppermost spout.

5. A gravity concrete mixer comprising a tilted to feed material to the receiving portion of the uppermost spout.

6. In a gravity concrete mixer, a charging and mixing hopper consisting of an open relatively Wide and shallow receptacle horizontally disposed, in which the ingredients may be spread in layers, one end of said receptacle being continued to form a relatively deep tapering spout terminating in a relatively narrow and deep discharge opening, means for tilting said hopper to discharge,

and means for receiving, and modifying the form and direction of, the stream of material so discharged while said material is being actuated by gravity.

In testimony of which, I hereunto aflix my hand, in the presence of two witnesses.

THOMAS L. SMITH.

Witnesses:

E. C. MANKLETOOO. [1 s] H. H. GERLAC-H. [1,. 51.]

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. 

